The way I have planned out my idea of how my character will interact will be that he can shoot the enemy, move left and right and go up and down the tower for better angles on the enemy. If I have extra time to work on this I may add on ability cool downs were the player could perhaps stun all enemies on the screen temporarily every 20 to 30 second cool down, they could maybe have a one shot ability which when used it of course can kill an enemy target in one shot.
The player will look around and aim at were ever the cursor is as well and enemies will spawn in waves near them which will head towards the tower to do damage so the player needs to be able to shoot back and do damage at them facing the cursor.
Games Design Course - Harrison Preston 